1. Field of the Invention
This invention relates to a specimen kit and a fabricating method thereof, and in particular, to a specimen kit applied to microscopes that is suitable for various types of specimens, especially liquid, magnetic and volatile specimens, and a fabricating method thereof.
2. Description of Related Art
Generally, specimens are observed in vacuo by electron microscopes as the molecules would scatter electrons. Since specimens have to be placed in a high vacuum and also have to be dehydrated, specimens containing liquids or volatile substances cannot be observed by utilizing electron microscopes.
Fujiyoshi et al. (U.S. Pat. No. 5,406,087) disclosed a specimen-holding device comprising polyvinyl ester films which transmit an electron beam and hold a specimen containing a liquid. The specimen-holding device also comprises O-rings pressed against the polymer films to isolate from the vacuum environment of the microscope. However, the polymer films of the device are easily damaged by long-term electron beam irradiation, and there is a need to modify general transmission electron microscopes (TEM) and specimen holders thereof so as to fit the device.
Suga et al. (Study by Monte-Carlo simulation of resolution improvement by energy filtering in Bio-TEM. Surf Interface Anal. 34, 657-659 (2002)) disclosed an instrument wherein a biological specimen is set in a conventional TEM but isolated from the high vacuum by a beryllium (Be) foil of 100 nm in thickness. However, general electron microscopes as well as the retainers and specimen holders thereof also have to be modified to fit the device.
A specimen holder for scanning electron microscopes (SEM) disclosed by Thuiberge et al. (Scanning electron microscopy of cells and tissues under fully hydrated conditions. Proc. Nat. Acad. Sci. U.S.A. 101(10), 3346-3351 (2004)) comprises a polyimide membrane. The polyimide membrane can endure long-term electron beam irradiation for its high melting point and outstanding stability; nevertheless, it cannot be applied to TEM.
As mentioned above, a specimen has to be dehydrated and placed in vacuum in traditional electron microscope. Although previous attempts have been made to address the inconvenience, such efforts have not been sufficient to adequately fulfill the increasing requirements for a continuous and real-time observation of a liquid specimen or a volatile specimen.